There are many instances when it is desirable, especially in the case of a fire, for persons to be provided with means for escape from upper floors of a building on the exterior thereof. Variously constructed apparatus have been heretofore designed for use in conjunction with elongated flexible tension members to allow persons to enjoy a reasonably controlled descent on the exterior of a building in the case of a fire or other emergency. Examples of previously patented devices of this type are disclosed in U.S. Pat. Nos. 219,511, 340,573, 439,263, 2,544,964 and 2,561,832. However, these previously patented devices are in some instances not wholly operable in the desired manner.